Note: The
following are excerpts from Richard Hughes' book, Ruby & Sapphire. If
you like what you see, order a
copy direct from the publisher.

"That which is beautiful is never too
costly, nor can anyone pay too much for that which gives pleasure
to all," said Abu Inan Farés, Sultan of Morocco,
on completion of a beautiful building at Fez. To emphasize his
delight, he refused to look at the architect's bill, but tore
it up and threw the fragments into the River Fez.

I gotta
love for Angela, I love Carlotta, too.
I no can marry both o' dem, so w'at I gona do?

Thomas
–1948]Between
Two Loves

MUCH
of human activity concerns discretionary ability. The world is
not composed of black and white, but of infinite shades of gray.
Not fixed in space and time, these shades undergo continuous change.
We are constantly called upon to make qualitative judgements. Such
decisions are made daily – they are part of life – and
our success in navigating life is closely tied to how we deal with
these challenges.

For
assistance, society has developed guidelines. While such
rules of thumb cannot predict the future of an individual
event, if they are based upon the experiences of a large
sampling of people, they have utility to the individual
over the long haul. But when they are based merely upon "faith," rather
than empirical methods, such beliefs constitute dogma.

There
is considerable evidence to suggest that many religious
and cultural dogmas were at one time based on empiricism.
For example, the prohibition against eating pork, widespread
in Judaic and Islamic cultures, is believed to have grown
out of the fact that, in desert societies, the keeping
of pigs wasted precious water, and so was a selfish activity
that harmed the group. But when such religions spread to
wetter climes, where there was plenty of water to go around,
the ban remained. Thus the problem. When empirical discovery
solidifies into immobile dogma, as with the above example,
the possibility of future discovery or change is ruled
out, to the detriment of all.

Similarly,
according to the European thought extant during the time
of Columbus, the earth was flat, and it was heresy to think
otherwise. This is the difference between empirical beliefs,
and those based upon faith alone, i.e., those based on
observation and first-hand experience, rather than assumption.

Figure 10.1 The
three dimensions of color10.1a: Three-dimensional view of a color
solid. (This illustration courtesy of Minolta
USA)

Ruby & sapphire grading:
A heretic's guide

Having now committed one heresy, the discussion
of religion, I shall proceed to commit another, discussion of colored stone
grading.

Comparable
to those who opposed the mere thought of Columbus sailing
into unknown waters, today many traders and gemologists
oppose even a discussion of systematic quality analysis
of colored stones. Akin to the priests of the Middle Ages,
who fought against translation of the Latin Bible into
vernacular languages, these high priests of the gem trade
apparently feel that only those properly initiated into
the "Great Order of Gemmarum et Lapidum" should
be allowed to dine at the quality-analysis table. Others
less fortunate must be content to scramble for the crumbs
of knowledge those on high deem suitable to toss their
way.

Grading
systems are as old as the gem trade itself. Witness ancient
India's Garuda Purana, dating back as far as
400 AD (Shastri, 1978), which classified the then-known
gems into categories on the basis of their characteristics.
Over the succeeding centuries, these systems have been
steadily refined. Diamond grading systems made their appearance
in the 20th century, but modern attempts at colored stone
grading date only from the late 1970s. Problems with some
of these early attempts have led many to condemn the very
idea of systematic grading. In the author's opinion,
this is a mistake.

Early
forays into colored stone grading were primitive, and today
many problems remain. This is to be found in the development
of anything new. Look at the first airplanes. Clumsy and
dangerous, they often killed their occupants. Today few
would argue against their use, but
in the beginning many did: "If humans were meant to
fly, they would have been born with wings" was the
typical refrain. I suppose if humans were meant to drive,
we would have been born with horns and bumpers.

10.1b: Vertical slice through the
color solid along the yellow-violet axis. Saturation increases
horizontally from the center, while lightness/darkness varies
along the vertical axis. Note that the highest saturation of
yellow is naturally much lighter than that for violet. A slice
along the green/magenta axis would show the highest saturations
to have a similar lightness.

In his excellent article on
the methods and benefits of colored stone grading, Nelson (1986)
cataloged a large variety of trade objections. In this author's
(RWH) opinion, the key criticisms are threefold:

Like the priests who opposed translation of
the Latin Bible into common languages, dealers are afraid
that colored stone grading will remove their trade advantages,
thus cutting the traditional gem dealer out of the picture.
[1]

In a business where the most complicated and
expensive piece of equipment is often an electronic balance,
traders dislike the thought of having to send their stones
out for lab grading.

Many colored stone dealers abhor the thought
that their trade might become like the diamond trade, where
stones with certificates are traded in an indiscriminate manner,
in some cases without ever viewing the gem. As a Geneva dealer
once told me: "My five-year old son can trade certificate
diamonds. It requires no knowledge, no training." This
is a real problem, one which gemologists must answer before
they can gain trade support for colored stone grading.

10.1c: Hue position is illustrated
by the color wheel, representing a vertical slice through
the color solid (the center is not shown). Mixing equal
amounts of the three additive primaries (red-orange,
violet, green) produces white, while equal mixtures of
subtractive primaries (cyan, magenta, yellow) results
in black.

Unfortunately,
the advantages to such a system are too often overlooked amidst
the bluster and rhetoric. These benefits are the increased consumer
confidence and thus, increased sales, which would follow adoption
of such standards. Much time would also be saved by adoption
of a standardized language for describing the appearance of colored
gems.

The
key to developing a successful colored stone grading system
will be in creating a language useful for communicating
the overall appearance of a gemstone. Once a gem is adequately
described, it is then up to the marketplace to determine
relative value. Attempts to assign relative values to each
grade will succeed only if the considerations of the real
marketplace are taken into account. To make these decisions,
gemologists must work closely with traders.

An
unfortunate paradox in the gem world (and one which is
also present in many other fields) is that traders, who,
by virtue of experience, are generally most qualified to
judge quality, must be disqualified from doing so because
of their bias. But traders must have input into
the system for it to succeed.

The
elements of quality

Quality is determined by reference
to the so-called 3 c's: color, clarity and
cut. While these factors are well defined for diamond,
no universally-accepted system exists for colored gems.
The following is based on the author's own extensive
experience.

Four blue sapphires showing
a variation in saturation and tone. Stone 1 possesses a light
tone and low saturation. Stone 2 is close to ideal in both
tone and saturation. Stone 3 has greater saturation than
Stone 2 in some areas, but its overall tone is too dark and
it shows too much extinction. Stone 4 is so dark in tone
that its saturation is reduced. Note that inclusions are
far more visible in stones of light tone than those of dark
tones. Photo: Wimon Manorotkul

Color and appearance in colored
gemstones

To
the color scientist, given an opaque, matt-finished object,
there are three dimensions to color:

Hue position: The
position of a color on a color wheel, i.e., red, orange, yellow,
green, blue and violet. Purple is intermediate between red
and violet. White and black are totally lacking in hue, and
thus achromatic ('without color'). Brown is not a
hue in itself, but covers a range of hues of low saturation
(and often high darkness). Classic browns fall in the yellow
to orange hues.

Saturation (intensity): The
richness of a color, or the degree to which a color varies
from achromaticity (white and black are the two achromatic
colors, each totally lacking in hue). When dealing with gems
of the same basic hue position (i.e., rubies, which are all
basically red in hue), differences in color quality are mainly
related to differences in saturation. The strong red fluorescence
of most rubies (the exception being those from the Thai/Cambodian
border region) is an added boost to saturation, supercharging
it past other gems that lack the effect.

Darkness (tone or value): The
degree of lightness or darkness of a color, as a function of
the amount of light absorbed. White would have 0% darkness
and black 100%. At their maximum saturation, some colors are
naturally darker than others. For example, a rich violet is
darker than even the most highly saturated yellow, while the
highest saturations of red and green tend to be of similar
darkness.

Figure
10.1 is a simplified illustration of the three dimensions
of color.

With
gems, we are not dealing with opaque, matt-finish object
of uniform color. Thus it is not enough to simply describe
hue position, saturation and darkness. We must also describe
the color coverage, scintillation and dispersion.

Color coverage can be influenced
by a variety of factors, including proportions, fluorescence
and inclusions. The round Burmese red spinel at left is strongly
fluorescent and the red emission adds extra power to the
red body color, covering up extinction. With the fine emerald-cut
Kashmir sapphire pictured at right, color coverage is improved
by the presence of tiny needlelike inclusions, which scatter
light across the stone, thus reducing extinction. This is
what gives Kashmir sapphires their incomparable velvety color.
Note that both of these gems have colors which are highly
saturate, making them highly desirable. Photos: Wimon Manorotkul,
John McLean

Color coverage: Differences
in inclusions, transparency, fluorescence, cutting, zoning
and pleochroism can produce vast differences in the color coverage
of a gem, particularly faceted stones. A gem with a high degree
of color coverage is one in which color of high saturation
is seen across a large portion of its face in normal viewing
positions. Tiny light-scattering inclusions, such as rutile
silk, can actually improve coverage, and thus appearance, by
scattering light into areas it would not otherwise strike.
The end effect is to give the gem a warm, velvety appearance
(Kashmir sapphires are famous for this). Red fluorescence in
ruby boosts this still further.

Color zoning
can also be influenced by color zoning,
an unevenness of color. The oval sapphire
above shows moderate color zoning. Moderate
to severe color zoning does impact quality,
and thus price. Color zoning is always
judged in the face-up position, in an 180° arc
from girdle to girdle, with the gem rotated
through 360°. Color irregularities
visible only through the pavilion generally
do not impact value. Photo: Wimon Manorotkul

Proper
cutting is vital to maximize color coverage. Gems
cut too shallow permit only short light paths,
thus reducing saturation in many areas. Such areas
are termed windows. Those cut too deep allow
light to exit the sides, creating dark or black
areas termed extinction. Areas which allow
total internal reflection will display the most
highly saturated colors. These areas are termed brilliance. Color
zoning can also reduce color coverage. Ideally,
no zoning or unevenness should be present. Pleochroism is
sometimes noticeable in ruby and sapphire. It typically
appears as two areas of lower intensity and/or
slightly different hue on opposite sides of the
stone. This is most notable when the table facet
lies parallel to the c axis. In
summary, a top-quality gem would display the hue
of maximum saturation across a large percentage
of its surface in all viewing positions. The closer
a gem approaches this ideal, the better its color
coverage.

Scintillation ('sparkle'): This
is an important factor in faceted stones. A gem cut with a
smooth, cone-shaped pavilion could display full brilliance,
but would lack scintillation. Thus the use of small facets
to create sparkle as the gem, light or eye is moved. In general,
large gems require more facets; small gems should have less,
for tiny reflections cannot be individually distinguished by
the eye (resulting in a blurred appearance).

Dispersion ('fire'): This
involves splitting of white light into its spectral colors
as it passes through two non-parallel surfaces (such as a prism).
The dispersion of corundum is so low (0.028) and the masking
effect of the rich body color so high, that it is generally
not a factor in ruby and sapphire evaluation.

Clarity

Clarity
is judged by reference to inclusions. Magnification can be
used to locate inclusions, but with the exception of inclusions
which might affect durability, only those visible to the naked
eye should influence the final grade.

Background
checks

When
you are examining a colored gemstone, act like a
cop – always do a background check.

The color of the background against which a gem is examined can
have a major effect on color. Which is why wily Burmese and Thai
miners traditionally offer up rubies to buyers on brass plates
or yellow table tops. The yellow background color counters the
bluish tint commonly present in ruby, making the gems appear
more red. Yellow cellophane-lined stone papers or brass tweezers
serve the same purpose. Don't be a sucker. For judging color,
a plain white background is best.

Figure
10.2 Rough
rubies at the mining areas in Burma and Thailand
are often displayed on brass plates. The yellow
color of the background makes the ruby appear
more red than it actually is. (Photo: Olivier
Galibert)

There are two key factors in
judging clarity. These are:

Visibility

Size: Smaller inclusions are less distracting,
and thus, better.

Number: Generally, the fewer the inclusions,
the better.

Contrast: Inclusions of low
contrast (compared with the gem's RI and color) are less
visible, and thus, better.

Location: Inclusions in inconspicuous
locations (i.e., near the girdle rather than directly under
the table facet) affect value less. Similarly, a feather perpendicular
to the table is less likely to be seen than one lying parallel
to the table.

Affect
on durability

Type: Unhealed cracks may not only be
unsightly, but also lower a gem's resistance to damage.
They are thus less desirable than a well-healed fracture. As
already mentioned, tiny quantities of exsolved silk may actually
improve a gem's appearance, and thus, value.

Location: A crack near the culet or
corner would obviously increase the chances of breakage more
than one well into the gem. Similarly, an open fracture on
the crown is more likely to chip than one on the pavilion.

Among
the problems of existing colored stone grading systems is that
the model chosen is based on diamond. While diamond does share
a number of quality factors with ruby and sapphire, others are
partly or wholly inappropriate. For example, beauty in diamond
is largely a function of the material's brilliance and dispersion
('fire'). Any inclusions which alter the path of light
could be detrimental to a diamond's appearance. [2]
Perfect clarity is thus the ideal. As described above, perfect
clarity is not necessarily the ideal for ruby and sapphire. While
fractures and most other inclusions do have a detrimental effect
on appearance and durability, small quantities of finely dispersed
inclusions (such as exsolved rutile silk) can actually improve
a richly colored gem's appearance. The watchword here
is small; too much silk decreases transparency by scattering,
reducing color saturation, and thus producing a more grayish color.
[3]

Cut
('make')

The
function of the cut is to display the gem's inherent
beauty to the greatest extent possible. Since this involves
aesthetic preferences upon which there is little agreement,
such as shape and faceting styles, this is the most subjective
of all aspect of quality analysis.

Evaluation
of cut involves five major factors:

Shape

This
describes the girdle outline of the gem, i.e. round, oval,
cushion, emerald, etc. While preferences in this area are
largely a personal choice, due to market demand and cutting
yields, certain shapes fetch a premium. For ruby and sapphire,
ovals and cushions are the norm. Rounds and emerald shapes
are more rare, and so receive a premium from about 10–20%
above the oval price. Pears and marquises are less desirable,
and so trade about 10–20% less than ovals of the
same quality. The shape of a cut gem almost always relates
to the original shape of the rough. Thus the prevalence
of certain shapes, such as ovals, which allow greatest
weight retention.

Cutting
style

The
cutting style (facet pattern) is also a rather subjective
choice. Again, because of market demand, manufacturing
speed and cutting yields, certain styles of cut may fetch
premiums. The mixed cut (brilliant crown/step pavilion)
is the market standard for ruby and sapphire.

If a gem is cut too shallow, light will pass
straight through, rather than returning to the eye as brilliance.
This is termed a "window" (right). In well-cut
gems, most light returns as brilliance (left). Brilliant
areas are those showing bright reflections. Extinction is
used to describe dark areas where little or no light returns
to the eye. Photo: Wimon Manorotkul

Proportions

The
faceted cut for ruby and sapphire is to create maximum brilliance
and scintillation in the most symmetrically pleasing manner.
Faceted gems feature two parts, crown and pavilion. The crown's
job is to catch light and create scintillation (and dispersion,
in the case of diamond), while the pavilion is responsible
for both brilliance and scintillation. Generally, when the
crown height is too low, the gem lacks sparkle. Shallow pavilions
create windows, while overly deep pavilions create extinction.
Again, proportions often are dictated by the shape of the rough
material. Thus to conserve weight, Sri Lankan material (which
typically occurs in spindle-shaped hexagonal bipyramids) is
generally cut with overly deep pavilions, while Thai/Cambodian
rubies (which occur as thin, tabular crystals) are often far
too shallow.

Depth percentage: In
attempting to quantify a gem's proportions, reference
is often made to depth percentage. This is calculated by taking
the depth and dividing it by the girdle diameter (or average
diameter, in the case of non-round stones). The acceptable
range is generally 60–80%.

Length-to-width ratio: Another
measurement that is used for non-round stones is the length-to-width
ratio. Overly narrow or wide gems of certain shapes are generally
not desirable.

Symmetry

Like
any finely-crafted product, well-cut gems display an obvious attention
to detail. A failure to take proper care evidences itself in a
number of ways, including the following:

Asymmetrical girdle outline

Off-center culet or keel line

Off-center table facet

Overly narrow/wide shoulders (pears and heart
shapes)

Overly narrow/deep cleft (heart shapes)

Overly thick/thin girdle

Poor crown/pavilion alignment

Table not parallel to girdle plane

Wavy girdle

Finish

Lack
of care in the finish department is less of a problem than the
major symmetry defects above, because it can usually be corrected
by simple repolishing. Finish defects include:

Facets do not meet at a point

Misshapen facets

Rounded facet junctions

Poor polish (obvious polishing marks
or scratches)

While
these guidelines may be useful, one must not become a slave to
them. In essence, the cut should display the gem's beauty
to best advantage, while not presenting mounting or durability
problems. If the gem is beautifully cut, things such as depth percentage
or length-to-width ratio matter not one bit. What works, works.

Influence of lighting on color

With any colored gemstone, the
color seen depends on the light source used to illuminate
it. Over time, gem dealers have come to rely on skylight
for their gem buying. Its major advantage is its strength,
which ruthlessly reveals flaws. The quantity of light coming
through even a modest-sized window is far greater than
even the strongest, color-balanced fluorescent tube (or
tubes). Another factor appears to be the large radiating
area, when compared with the most artificial lights.

Figure 10.3 Lighting
can have a dramatic effect on the appearance of any colored
gem. Incandescent lighting (left) is rich in red, orange and
yellow wavelengths and thus pushes an object's color in that
direction. In contrast, skylight (right) is more balanced,
pushing the color in the opposite direction. (Illustration:
Minolta)

Latitude
may also affect a stone's color, simply because skylight
is stronger in the tropics. As a result, gems bought in the tropics
will appear slightly darker when taken to more temperate climes.
It is a slight, but nevertheless, noticeable difference. Surprisingly,
north skylight (or south skylight in the southern hemisphere)
is actually stronger on cloudy days.

Another
factor is the Purkinje shift. [4]
In bright light, the eye is more sensitive to red; conversely,
in dim light the eye is more sensitive to blue-violet light.
Thus the color of blue sapphires would be slightly enhanced
in dim lighting.

The
question of north skylight

North
daylight (skylight, as opposed to direct sunlight) has
become the standard, because it produces the least glare,
but blind adherence to such gemological dogma is just as
bad as blind adherence to religious dogma. If you live
north of the Tropic of Cancer (Europe, North America, Japan,
China, etc.), north skylight will provide the least glare
year round, because the sun always passes through the southern
portion of the sky. This is especially true the farther
north one goes. The opposite holds true for those who reside
south of the Tropic of Capricorn (in the southern hemisphere),
where the least glare is found using south skylight.

What
about those who live in the tropics? If they are north
of the equator, north skylight is best, except May-July,
when south skylight is preferred. For the tropics south
of the equator, south skylight is best, except from Nov.-Jan.,
when north skylight is preferred. And if you live right
on the equator, use north skylight from Oct.-Feb., and
south skylight from April-August. During March and Sept.,
either north or south skylight can be used.

Time
of day

Even
skylight changes throughout the day. Generally speaking,
rubies (and other red stones) look best during the midday
hours. Sapphires, in contrast, look best in the early morning
or late afternoon. If you are buying, this means that rubies
should be purchased early or late in the day, while sapphires
are best bought near midday, thereby preventing a surprise
when the stone is examined under another lighting condition.

The
above is in contrast to what is often reported (Newman,
1994, p. 38). While direct sunlight is far more red at
sunrise and sunset, the skylight is actually more
blue. Since we use skylight, not direct sunlight, to illuminate
gems, blue color will be enhanced early and late in the
day. Similarly, the skylight at noon is less blue, thus
enhancing the color of rubies in the middle of the day.

Weather
and pollution

How
might clouds or pollution affect color? Heavily-polluted
or cloudy skies will result in more grayish (less blue)
skylight, thus improving the appearance of rubies (as opposed
to sapphires).

Above Left. The Buddhist temple
at Swayambunath, Nepal, silhouetted against a deep blue sky.
It is obvious that such skylight would enhance the appearance
of blue stones.

Artificial
lighting

Some
type of artificial light is obviously the answer to neutralize
the above factors. Many dealers today do their buying under
special daylight lamps designed to simulate true north
daylight, with a color temperature of approximately 5000–6100°Kelvin.
Generally speaking, while their color balance is similar
to north daylight, the fluorescent tubes used suffer from
low light output. A 20-watt fluorescent daylight tube at
a distance of 30 cm produces about 1000 lux of illumination,
while a north-facing window in Bangkok averages 6000 lux.

The
answer appears to be short-arc xenon lamps. While rather
expensive (compared to fluorescent lamps), they have a
continuous output (like daylight), 6000°K color temperature,
and produce illumination levels comparable to north daylight.

For
an excellent summary of the entire lighting question, see
Sersen & Hopkins (1989) and Sersen (1990), from which
the above is derived.

Viewing geometry & background

Gems are designed to be mounted in
jewelry and viewed from predetermined angles. This is generally
face-up, with the gem viewed in a 180° arc from girdle to
girdle. Thus it is only logical that all quality determinations
be made with the naked eye under the same viewing geometry. It
is important that the gem be rotated through 360° in the
girdle plane, so that its appearance is seen from all angles,
just as it would be when mounted in jewelry.

To
ensure reproducibility and repeatability, a standardized light
source against a standardized, neutral background (white is best)
at a standardized distance should be used. The practice in diamond
grading of judging body color through the pavilion facets is
madness, and has no place in colored stone grading. [5]

Summary of quality

The appearance of a colored gem is
a combination of many separate factors, each of which is related
to, and affect, the others. It is precisely the complexity of
these intertwined relationships that has bedeviled previous attempts
to quantify quality. And yet, every time a dealer buys a gem,
a quick mental analysis is made, usually within seconds. In grading
any gem, one must be cognizant of, but not become lost in, the
details. When all the minutiae has been pored over ad infinitum,
ad nauseam, take a step back and simply look at the gem. In
the age of high-powered microscopes this may constitute a radical
concept, but one which is necessary.

Fine
precious stones are comparable to great works of art.
Like a painting, to appreciate it, one must view the
whole, not just the parts.

Pricing
factors

Prices of Genuine Jewels
The prices of jewels are not stable. There is no law governing their
prices, and there is no reason why these prices should not fluctuate
with time and place. Each country, each nation carries its own temper.
Furthermore, at one time nobles begin to sell them off and at others,
to stock them. Stones are plentiful at one time and scarce at another.
God grants honour to some and disgrace to others.

al-Biruni,
11th century ADKitab
al-Jamahir fi Ma'rifat al-Jawahir

One of the great mysteries for
novices is the relationship between price and quality. In a perfect
world, price would directly relate to quality/weight/rarity. Unfortunately,
Planet Gem is far from symmetrical. Market factors can have as
much, or even greater, impact on prices as does quality. Prices
are influenced by the following factors:

Quality: Better qualities are
more rare than lower qualities of the same size (see previous
section).

Weight: Bigger stones are more
rare, and so more expensive per carat than the same quality
of a smaller size.

Market factors: This is
the great intangible. Market factors can dramatically affect
price.

Weight

Generally,
as a gem's weight increases, so does the per carat price.
This is shown in Figure 1.6.

Figure 10.6 Graph
representing the relationship between price and quality/weight/rarity.
Note that this is not a linear relationship. Price increases
more quickly as quality/weight/rarity increases.

Such
a relationship has long been known, and was first quantified
by Villafane in 1572, for diamonds. Today it is most commonly
referred to as the 'Indian Law' or 'Tavernier's
Law', and works as follows (Lenzen, 1970):

Wt2 x C = price per stone

Weight
of gem

= 5 ct (Wt)

Cost
of a 1-ct gem of equal quality

= $1000 (C)

Calculation:
5 x 5 x 1000

= $25,000 total stone price

The
following shows how the price of a gem might increase with this
formula applied using a $1000/ct base price.

Weight

Total stone price

1
ct

$1000

2
ct

$4000

3
ct

$9000

4
ct

$16,000

5
ct

$25,000

10
ct

$100,000

Unfortunately, things were not
so simple, even for diamonds in the time of Tavernier. The law
could not accurately predict the price of diamond below 1 ct, and
there were also problems with exceptionally large stones. But it
does give a general idea of how prices increase with size.

Carat
psychology

the
case of many gems, including ruby and sapphire, psychological
(but all too real) price jumps occur at certain weights.
For example, a 0.99-ct ruby might be worth significantly
less than one which weighs 1.05 ct. The 1.05 ruby would
be worth more than one which weighed exactly 1.00 ct,
as repolishing a 1.00-ct stone (or weighing it on someone
else's scale) might send it below the important
1-ct barrier. Similar psychological weight hurdles are
found at the 2, 5, 10, 20, 50 and 100-ct levels.

Market
factors

Just
a few of the market factors that influence price include:

Market supply vs. demand: Items
which are plentiful and/or in low demand will be cheaper than
those which are rare and/or in high demand.

Financial situation of the seller: Sellers
who need money will obviously be more flexible on price. Similarly,
those who are not in need are less willing to reduce their
price.

Seller's business overhead: Prices
can vary dramatically depending on the seller's overhead.
A cup of coffee purchased by a street vendor may cost only
a few cents; the same cup of coffee at a 5-star hotel in the
same city may cost 10–20 times more, due to the hotel's
higher overhead.

Buyer's sales prospect: Buyers
who have a customer waiting for an item are often willing to
pay higher prices.

Buyer/seller
personal relationship: No one likes to do business with
unhappy or abusive people. When the buyer and seller enjoy
each other's company, they often make special provisions
for one another.

Personal situation surrounding the
sale: The author has seen buyers pay above-average prices
for goods for a variety of reasons. These have ranged from
trying to impress one's girlfriend, [6]
to buying something simply to prevent a competitor from purchasing
the same goods.

Chapter 10 continues with…

Notes

The
idea of the traditional dealer is one sorely in need of definition,
considering that the tradition of many so-called "traditional" gem
dealers dates back less than 30 years. [ return to
text ]

Unfortunately,
the current diamond-grading system, largely based on
the GIA model, has applied this idea in an overly zealous
manner. Thus even a single microscopic inclusion, which
in no way affect a diamond's appearance, removes
it from the top clarity category. Many of the upper clarity
grades have absolutely no visible difference in naked-eye
appearance (see Hughes, 1987b, 1991). [ return to
text ]

Stones
which look good from a distance, but upon closer examination
exhibit clarity problems are termed bluff stones.[ return to
text ]

Johannes
von Purkinje, a Czech physiologist, observed while
walking in the fields in 1825 that blue flowers appeared
brighter at dawn than at midday (Varley, 1983). [ return to
text ]

Nor
in diamond grading, but that is another subject. [ return to
text ]

Apparently
the lady was suitably impressed, for she is now his
wife. [ return to
text ]

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